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Associations of the APOC3 rs5128 polymorphism with plasma APOC3 and lipid levels: a meta-analysis.
Song, Y, Zhu, L, Richa, M, Li, P, Yang, Y, Li, S
Lipids in health and disease. 2015;:32
Abstract
BACKGROUND Studies of the association between the apolipoprotein C3 gene (APOC3) rs5128 polymorphism and plasma levels of apolipoprotein C3 (APOC3) and lipids have reported apparently conflicting findings. This meta-analysis aimed to investigate the associations of the rs5128 polymorphism with fasting APOC3 and lipid levels. METHODS The following information was abstracted for each study: ethnicity, age, sex, health condition, sample size, genotyping and lipid assay methods, mean and standard deviation or standard error by genotypes for APOC3 and lipid variables. There were 42 eligible studies with 23846 subjects included in this meta-analysis. A dominant model was used for this meta-analysis. RESULTS The results showed that the carriers of the variant allele G had higher levels of APOC3 [standardized mean difference (SMD): 0.22, 95% confidence interval (CI): 0.12-0.31, P<0.00001], triglycerides (TG) (SMD: 0.33, 95% CI: 0.23-0.44, P<0.00001), total cholesterol (TC) (SMD: 0.15, 95% CI: 0.09-0.22, P<0.00001), and low-density lipoprotein cholesterol (LDL-C) (SMD: 0.11, 95% CI: 0.04-0.17, P=0.001) than the non-carriers. No significant association between the APOC3 rs5128 polymorphism and lower levels of high-density lipoprotein cholesterol (HDL-C) was detected under the dominant model (SMD: -0.03, 95% CI: -0.06-0.01, P=0.156). CONCLUSIONS The results from the present meta-analysis demonstrate a significant association between the APOC3 rs5128 polymorphism and higher levels of APOC3, TG, TC and LDL-C, but further studies are needed to elucidate the underlying mechanisms.
2.
Effect of genetic variation in the organic cation transporter 2 on the renal elimination of metformin.
Chen, Y, Li, S, Brown, C, Cheatham, S, Castro, RA, Leabman, MK, Urban, TJ, Chen, L, Yee, SW, Choi, JH, et al
Pharmacogenetics and genomics. 2009;(7):497-504
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Abstract
OBJECTIVE The goal of this study was to determine the effect of a genetic variant in the organic cation transporter 2 (OCT2), OCT2-808G/T, which results in an amino acid change, A270S, on the pharmacokinetics of the antidiabetic drug, metformin. METHODS The uptake of metformin was performed in stably transfected HEK-293 cells expressing the empty vector (MOCK), the reference OCT2-808G, and the variant OCT2-808T. Healthy individuals with known OCT2 genotypes [14 homozygous for the OCT2 reference allele (808G/G) and nine heterozygous for the variant allele (808G/T, *3D)] were recruited to this study. Metformin concentrations in plasma and urine were measured by liquid chromatography-tandem mass spectrometry method. Creatinine levels were also measured in plasma and urine. Pharmacokinetic parameters were evaluated for both the groups. RESULTS We observed that in HEK-293 stably transfected cells, OCT2-808T had a greater capacity to transport metformin than did the reference OCT2. Metformin pharmacokinetics was characterized in 23 healthy volunteers of Caucasian and African-American ancestries. We observed that the renal clearance (CL(R)) and the net secretion (SrCL(R)) of metformin were significantly different between the volunteers heterozygous for the variant allele (808G/T), and the volunteers homozygous for the reference allele (808G/G) (P<0.005). Multivariate analysis revealed that OCT2 genotype was a significant predictor of CL(R) and SrCL(R) of metformin (P<0.01). CONCLUSION We conclude that genetic variation in OCT2 plays an important role in the CL(R) and SrCL(R) of metformin in healthy volunteers.